Spectroscopic study of solid-state photoreaction in organic crystals: photopolymerization of the dimethyl ester of p-phenylenediacrylic acid

✍ Scribed by Manash Ghosh; T. K. Mandal; Subhasis Chakrabarti; T. N. Misra

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 229 KB
• Volume: 29
• Category: Article
• ISSN: 0377-0486
• DOI: 10.1002/(sici)1097-4555(199809)29:9<807::aid-jrs306>3.0.co;2-7

✦ Synopsis

The crystalline-state photopolymerization reaction mechanism in the dimethyl ester of p-phenylenediacrylic acid (p-PDAMe) was investigated. Raman phonon spectroscopic studies revealed that the reaction proceeds by a heterogeneous mechanism as the reactant and the product do not form a solid solution. The appearance of sharp phonon bands in the product, however, suggests that the photopolymerized p-PDAMe lattice is highly ordered. The absence of a large StokesÏ shift and the considerable overlap between the excitation and the emission bands show that exciton-phonon coupling is weak in the monomer crystal. Polymerization occurred by formation of cyclobutane rings through the aliphatic CxC bond and was conÐrmed by infrared and Raman spectroscopy.

1998 John ( Wiley & Sons, Ltd.